The 4WITAR-B is a 4-wire, photoelectric i3 smoke detector with isolated thermal sensor, built-in sounder, and Form C relay.

To reduce the likelihood of nuisance alarms, all i3 detectors are equipped with both drift compensation and smoothing algorithms. These capabilities minimize both short- and long-term causes of nuisance alarms, such as RF interference and dust accumulation. When connected to the 2W-MOD2 loop test/ maintenance module or an i3 Ready™ panel, 2-wire i3 detectors can generate a remote maintenance signal when in a maintenance or freeze trouble condition. To measure the sensitivity of any i3 detector, the SENS-RDR displays the reading, in terms of percent-per-foot obscuration, within seconds.

i3 has red and green LEDs to simplify local status indication during power-up, standby, alarm, maintenance, and freeze trouble conditions. When in alarm, i3 sounder models generate an 85 dB temporal tone. If connected to the RRS-MOD reversing relay/synchronization module, all i3 sounders on the loop will activate when one detector is in alarm. The RRS-MOD also synchronizes i3 sounder output to ensure a clear audible signal.